Process for the extraction and elimination of deleterious material from natural manganese dioxide and concentrate of manganese dioxide obtained by said process

Abstract

This invention relates to a new process for the extraction and elimination of deleterious material present in natural manganese dioxide (NMD), as well as in natural manganese dioxide obtained by such process. The process involves treating NMD with a HCl and water mixture in a reactor while stirring and heating the mixture. The heating temperature of the reactor is maintained in a predetermined range. The reactor is then fed with an amount of crushed NMD ore. A leaching reaction of said NMD ore with the HCl is produced by leaching for a period of time. Subsequently, the contents of the tank are filtered, washed and dried to recovery the concentrate of manganese dioxide substantially free of deleterious material.

What is claimed is:  
     
       1. A process for extracting and eliminating deleterious material from natural manganese dioxide (NMD) comprising: 
       feeding a reactor with a solution consisting of HCl and water, heating said solution with stirring to a reaction temperature ranging from about 80° C. to 95° C. and maintaining the HCl concentration in said solution within a range of about 9% to 25% w/w;  
       maintaining the temperature of said HCl solution in said reactor at a temperature of from about 80° C. to 95° C.;  
       feeding said reactor containing said HCl solution with crushed NMD ore to provide a reaction pulp concentration of from about 10% to 40%;  
       leaching said reaction pulp with said HCl solution for a period of about 10 to 60 minutes;  
       filtering the contents of said reactor to recover the concentrate of manganese dioxide (MnO 2 ); and  
       washing and drying the recovered concentrate of MnO 2 .  
     
     
       2. The process of claim  1 , wherein said deleterious material is Cu, Ni, Co, Fe, Al or K. 
     
     
       3. The process of claim  1 , wherein said HCl and water solution is recycled to increase the concentration and solubility levels of Fe and heavy metals in respect to solubility levels of MnO 2  and Mn. 
     
     
       4. The process of claim  1 , wherein the recovered concentrate of MnO 2  is dried at a temperature of about 60° C. 
     
     
       5. The process of claim  1 , wherein the recovery of said MnO 2  is from about 70% to 90%. 
     
     
       6. The process of claim  1 , wherein said HCl concentration is about 14% w/w, the reaction temperature is about 90° C., the reaction time is about 40 minutes, and the recovery of MnO 2  under such conditions is about 72%. 
     
     
       7. The process of claim  1  wherein said HCl concentration is about 14% w/w, the reaction temperature is about 90° C., the reaction time is about 40 minutes, and the recovery of MnO 2  under such conditions is about 72%.